Gannett President and CEO Gracia Martore called the acquisition an “important step” in Gannett’s diversification and said it will significantly improve the company’s cash flow and financial strength.

The acquisition will make Gannett, based in McLean, Va., one of the country’s largest owners of major network affiliates, reaching nearly one-third of U.S. households. It nearly doubles Gannett’s portfolio from 23 to 43 stations and gives it 21 stations in the country’s top 25 television markets.

Gannett expects the deal to boost its adjusted earnings by 50 cents per share within the first 12 months and generate $175 million in annual cost savings within three years after closing.

Belo President and CEO Dunia Shive said the sale is an “outstanding and financially compelling transaction” for his company’s shareholders.

The deal, which has been approved by the boards of both companies, is expected to close by the end of 2013. It needs approval from the Federal Communications Commission and at least two-thirds of Belo shareholders.

Belo executives and shareholders representing about 42 percent of the company’s voting power have agreed to support the sale, the companies said.